Common brownie baking mistakes are overmixing the batter, using cold eggs, cutting the brownies before they cool completely and even overbaking the brownies.
Overbaking the brownies is the most common mistake when baking brownies, which leads to dry, cakey textures for the brownies instead of fudgy textures that brownies should have.
When baking brownies, the brownies should be removed from the oven when a toothpick comes out of the brownies with a few moist crumbs and not completely clean as the brownies also continue to cook while they are cooling.
If the toothpick comes out completely clean then they should be baked more until the toothpick comes out of the brownies with a few moist crumbs.
Overmixing the brownie batter develops the gluten in the brownie batter, which results in a cake like or tough texture, instead of the dense and fudgy texture that brownies should have.
Using cold butter or cold eggs in brownie mix is also a common mistake when baking brownies as the ingredients including the eggs and butter should be at room temperature to properly emulsify the ingredients, otherwise it can result in a broken or uneven brownie batter.
And cutting brownies too soon while warm also ruins the texture of the brownies and causes the brownies to crumble.
So before cutting the brownies, the brownies should be cooled completely to ensure clean fudgy square brownies.
Other common mistakes when baking brownies are using the wrong size baking pan, using low quality chocolate, not lining the baking pan and even not measuring the flour properly.
Not measuring the flour properly and scooping the flour directly into the bowl with a measuring cup also packs the flour down and adds too much flour that makes your brownies dry.
When measuring flour for the brownies you should use a scale or the spoon and level method.
And forgetting to use parchment paper or failing to grease the baking pan properly causes sticking of the brownies, which makes it impossible to remove the brownies cleanly and easily.
Using a baking pan that is too large or too small also alters the baking times and thickness of the brownies and so an 8x8 inch or 9x9 inch straight sided metal baking pan is often recommended for baking brownies.
And because the chocolate is the primary flavor in brownies, using low quality chocolate or cocoa powder results in a taste that is lackluster or not as great.